feat: 全排列问题

Author: sl1673495

递归与回溯/全排列-46.js

@@ -0,0 +1,24 @@
+/**
+ * @param {number[]} nums
+ * @return {number[][]}
+ */
+let permute = function (nums) {
+  let n = nums.length
+  if (n === 1) {
+    return [nums]
+  }
+
+  let res = []
+  for (let i = 0; i < n; i++) {
+    let use = nums[i]
+    let rest = nums.slice(0, i).concat(nums.slice(i + 1, n))
+    let restPermuteds = permute(rest)
+    for (let restPermuted of restPermuteds) {
+      res.push(restPermuted.concat(use))
+    }
+  }
+
+  return res
+}
+
+console.log(permute([1, 2, 3]))

递归与回溯/分割回文串-131.js

@@ -0,0 +1,51 @@
+/**
+ * @param {string} s
+ * @return {string[][]}
+ */
+
+let partition = function (s) {
+  let n = s.length
+  let ret = []
+  let find = function (start, prev) {
+    // 最少分割一个字符 最多分割到末尾前一位
+    for (let i = 1; i <= n; i++) {
+      let end = start + i
+      let cur = s.substring(start, end)
+      if (cur) {
+        let res = prev.concat(cur)
+        if (isPalindrome(cur)) {
+          if (end === n) {
+            ret.push(res)
+          } else {
+            find(start + i, res)
+          }
+        }
+      }
+    }
+  }
+  find(0, [])
+  return ret
+}
+
+function isPalindrome(s) {
+  if (!s) {
+    return false
+  }
+  let i = 0
+  let j = s.length - 1
+
+  while (i < j) {
+    let head = s[i]
+    let tail = s[j]
+
+    if (head !== tail) {
+      return false
+    } else {
+      i++
+      j--
+    }
+  }
+  return true
+}
+
+console.log(partition("aab"))